debug/elf: define R_PPC64_REL24_P9NOTOC

This relocation is not (yet?) defined in ELFv2, but has been added to
gnu gas a couple years ago. It is the same reloc as
R_PPC64_REL24_NOTOC, but hints power10 instructions should not be
emitted.

See binutils commit 7aba54da426b9999085d8f84e7896b8afdbb9ca6.

Fixes #60348

Change-Id: Ie953cd7bf1ffc621b498d4dbebb5de1231833c8f
Reviewed-on: https://go-review.googlesource.com/c/go/+/496918
Run-TryBot: Paul Murphy <murp@ibm.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

api/next/60348.txt

@@ -0,0 +1,2 @@
+pkg debug/elf, const R_PPC64_REL24_P9NOTOC = 124 #60348
+pkg debug/elf, const R_PPC64_REL24_P9NOTOC R_PPC64 #60348

src/debug/elf/elf.go

@@ -2763,6 +2763,7 @@ const (
 	R_PPC64_PLTSEQ_NOTOC       R_PPC64 = 121
 	R_PPC64_PLTCALL_NOTOC      R_PPC64 = 122
 	R_PPC64_PCREL_OPT          R_PPC64 = 123
+	R_PPC64_REL24_P9NOTOC      R_PPC64 = 124
 	R_PPC64_D34                R_PPC64 = 128
 	R_PPC64_D34_LO             R_PPC64 = 129
 	R_PPC64_D34_HI30           R_PPC64 = 130
@@ -2926,6 +2927,7 @@ var rppc64Strings = []intName{
 	{121, "R_PPC64_PLTSEQ_NOTOC"},
 	{122, "R_PPC64_PLTCALL_NOTOC"},
 	{123, "R_PPC64_PCREL_OPT"},
+	{124, "R_PPC64_REL24_P9NOTOC"},
 	{128, "R_PPC64_D34"},
 	{129, "R_PPC64_D34_LO"},
 	{130, "R_PPC64_D34_HI30"},